Lower growth arrest-specific 5 level in endometrium is related to endometriosis via promoting cell proliferation and angiogenesis.

Long noncoding RNAs are a group of more than 200 nt, nonprotein coding RNAs, some of which are dysregulated in many pathophysiological processes including endometriosis. This study aims to clarify the roles of dysregulated growth arrest-specific 5 (GAS5) in patients with endometriosis, and unveil the underlying mechanisms. We obtained endometrium samples from 37 patients with endometriosis and 23 controls without endometriosis. Primary endometrial stromal cells (ESCs) and endothelial cells were separated from the endometrium. Levels of GAS5 were quantified using quantitative real-time polymerase chain reaction, and levels of p27, cleaved caspase-3, cleaved poly (ADP-Ribose) polymerase 1, vascular endothelial growth factor A, tissue inhibitor of metalloproteinases 3 (TIMP3), and trypsin-modified soy protein 10 were assessed by immunoblotting. Cell viability was examined using MTT assays, and the cell cycle and apoptosis were analyzed by flow cytometry. Endothelial cell tube formation capacity was assayed in vitro. GAS5 and p27 levels were found lower in the endometrium samples from patients with endometriosis. Primary ESCs from patients with endometriosis had increased viability, reduced apoptosis, and a relatively uncontrolled cell cycle. Gain- and loss-of-function studies confirmed that GAS5 regulated p27 expression in ESCs. Furthermore, GAS5 level was relatively low in primary endothelial cells from patients with endometriosis and GAS5 acted as an angiogenesis inhibitor by regulating the miR-181c-TIMP3 axis. Thus, lower GAS5 level in endometrium might be related to endometriosis by regulating cell proliferation, apoptosis, cell cycle, and angiogenesis.